The present invention relates generally to a guard for use with a woodworking tool and, more particularly, to a guard for use with a jointer in which the guard includes a featherboard for biasing a workpiece into contact with a guide fence of the jointer.
A typical jointer includes a work supporting table, a cutting element or cutter head and a guide fence wherein the cutting table is formed with front and rear halves and a table apron extending along an outer edge of the front and rear halves opposite from the cutting element and the fence. The front and rear halves are vertically adjustable relative to each other such that, as the difference in height between the two halves is increased, the amount that the cutting element is exposed to a workpiece is also increased. Thus, the amount of material cut from a workpiece is dependent upon the height difference between the front and rear halves of the table and it is essential that the workpiece be held in contact with these table portions as it is moved past the cutting element.
In a typical jointing operation, the operator must force the workpiece sideways into the guide fence while also pushing down to insure that the workpiece is in constant contact with the table top. The operator initially applies a greater force to the workpiece resting on the rear half of the table and, as the workpiece progresses through the jointer, the operator must transfer a greater amount of force to the portion of the workpiece resting on the front half of the table. Thus, the hands of the operator are typically located either above or to the side and in close proximity to the cutting element during the jointing operation which may lead to a dangerous situation if a kickback of the workpiece should occur wherein the workpiece is kicked out of the jointer such that it no longer separates the operator's hand from the cutting element.
The danger presented by jointers has to a large extent been eliminated by the use of guard eements which are typically mounted to the jointer apron and are biased into position over the cutting element when a workpiece is not being fed through the jointer. A problem with current guard designs is that as the workpiece approaches the guard it pushes the guard away from the cutting element such that a path is cleared between the guard and the guide fence. While such a guard design has been adequate for protecting the operator's fingers from the cutting element in most situations, occasions may still arise where the jointer kicks the workpiece out of position between the guard and the guide fence in a manner such that the operator's fingers may enter the space between the guard and the fence before the guard can swing back into position over the cutting element. Further, the movement of the guard away from the fence is not limited in any manner such that under certain circumstances the guard may expose more of the cutting element than is necessary and thereby increase the risk of injury.
U.S. Pat. No. 2,895,517 to Rhett discloses a guard for jointers which is designed to overcome some of the above-mentioned problems. The guard disclosed by Rhett includes a housing which carries a plurality of fingers which are movable in a direction perpendicular to the guide fence of the jointer. As a workpiece enters the jointer, an angle plate causes the fingers to move out of the path and to a position spaced from the workpiece until the trailing edge of the workpiece passes beyond the angled plate, at which time the fingers move into the space behind the rear edge of the workpiece. While the guard of Rhett addresses the problem of covering the cutting space as the workpiece passes out of the cutting area to thereby prevent the operator's fingers from contacting the cutting element, this guard is still ineffective in preventing injuries which might occur as a result of the guard moving away from the guide fence a distance greater than the width of the workpiece and does not address the problems which may occur during kickback of the workpiece from the jointer cutting element.
Accordingly, there is a need for a guard for use with a jointer in which the movement of the guard away from the guide fence may be limited to a distance substantially equal to the width of the board being cut such that the exposure of the cutting element may be minimized. In addition, there is a need for a guard which will provide increased control of the workpiece as it is fed through the jointer whereby the amount of force applied by the operator toward the workpiece, and thus toward the cutting element of the jointer, is also minimized.
Further, there is a need for a jointer guard which is capable of decreasing the severity of kickback situations during the operation of the jointer such that the danger using from the operator losing control of the workpiece is kept to a minimum.